# Server Constraints

{% columns %}
{% column %}
{% content-ref url="server-constraints/server-constraints-overview" %}
[server-constraints-overview](https://mariadb.com/docs/server/architecture/server-constraints/server-constraints-overview)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Provides a high-level overview of how MariaDB Server enforces data integrity through various architectural constraint types.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="server-constraints/auto\_increment-constraints" %}
[auto\_increment-constraints](https://mariadb.com/docs/server/architecture/server-constraints/auto_increment-constraints)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Explains the limitations and behavior of `AUTO_INCREMENT` columns, including how they handle maximum values and gaps in sequences.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="server-constraints/foreign-key-constraints" %}
[foreign-key-constraints](https://mariadb.com/docs/server/architecture/server-constraints/foreign-key-constraints)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Details the requirements and limitations for defining foreign keys to ensure referential integrity between tables.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="server-constraints/not-null-constraints" %}
[not-null-constraints](https://mariadb.com/docs/server/architecture/server-constraints/not-null-constraints)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Describes how `NOT NULL` constraints prevent `NULL` values from being stored in specific columns.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="server-constraints/primary-key-constraints" %}
[primary-key-constraints](https://mariadb.com/docs/server/architecture/server-constraints/primary-key-constraints)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Outlines the rules for primary keys, which uniquely identify each record in a table and cannot contain `NULL` values.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="server-constraints/unique-constraints-with-mariadb-enterprise-server" %}
[unique-constraints-with-mariadb-enterprise-server](https://mariadb.com/docs/server/architecture/server-constraints/unique-constraints-with-mariadb-enterprise-server)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Explains the specific implementation and considerations for unique constraints when using MariaDB Enterprise Server.
{% endcolumn %}
{% endcolumns %}